pt.iscte.dcti.expressionsview.ProjectClassLoader.java Source code

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Here is the source code for pt.iscte.dcti.expressionsview.ProjectClassLoader.java

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/*******************************************************************************
 * Copyright (c) 2014 Andre L. Santos.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     Andre L Santos - developer
 ******************************************************************************/
package pt.iscte.dcti.expressionsview;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;

import org.eclipse.core.resources.IProject;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.jdt.core.IClasspathEntry;
import org.eclipse.jdt.core.IJavaProject;
import org.eclipse.jdt.core.JavaCore;
import org.eclipse.jdt.core.JavaModelException;

class ProjectClassLoader extends ClassLoader {
    private IProject project;

    private Map<String, Class<?>> map;

    public ProjectClassLoader(ClassLoader parent, IProject project, Map<String, Class<?>> map) {
        super(parent);
        this.project = project;
        this.map = new HashMap<String, Class<?>>(map);
    }

    public static boolean existsInLibrary(IProject project, String name) {
        try {
            IJavaProject javaProj = (IJavaProject) project.getNature(JavaCore.NATURE_ID);
            IClasspathEntry[] classpath = javaProj.getRawClasspath();
            for (IClasspathEntry entry : classpath) {
                if (entry.getEntryKind() == IClasspathEntry.CPE_LIBRARY) {
                    IPath p = entry.getPath();
                    File f = p.append(name.replace('.', '/') + ".class").toFile();
                    if (f.exists())
                        return true;
                }
            }
        } catch (CoreException e1) {
            e1.printStackTrace();
        }
        return false;
    }

    public Class<?> loadClass(String name) throws ClassNotFoundException {
        if (name.startsWith("java.") || name.startsWith("sun."))
            return getParent().loadClass(name);

        if (map.containsKey(name))
            return map.get(name);

        byte[] classData = null;
        try {
            File file = project.getLocation().append("bin").append(name.replace('.', '/') + ".class").toFile();
            if (file.exists())
                classData = getBytesFromFile(file);
            else {

                IJavaProject javaProj = (IJavaProject) project.getNature(JavaCore.NATURE_ID);
                try {
                    IClasspathEntry[] classpath = javaProj.getRawClasspath();
                    for (IClasspathEntry entry : classpath) {
                        if (entry.getEntryKind() == IClasspathEntry.CPE_LIBRARY) {
                            IPath p = entry.getPath();
                            File f = p.append(name.replace('.', '/') + ".class").toFile();
                            if (f.exists()) {
                                classData = getBytesFromFile(f);
                            }
                        }
                    }
                } catch (JavaModelException e) {
                    e.printStackTrace();
                }

            }
        } catch (IOException e) {
            e.printStackTrace();
        } catch (CoreException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        if (classData == null)
            throw new ClassNotFoundException(name);

        Class<?> clazz = defineClass(name, classData, 0, classData.length);

        if (!map.containsKey(name))
            map.put(name, clazz);

        return clazz;
    }

    public static byte[] getBytesFromFile(File file) throws IOException {
        InputStream is = new FileInputStream(file);

        // Get the size of the file
        long length = file.length();

        if (length > Integer.MAX_VALUE) {
            // File is too large
        }

        // Create the byte array to hold the data
        byte[] bytes = new byte[(int) length];

        // Read in the bytes
        int offset = 0;
        int numRead = 0;
        while (offset < bytes.length && (numRead = is.read(bytes, offset, bytes.length - offset)) >= 0) {
            offset += numRead;
        }

        // Ensure all the bytes have been read in
        if (offset < bytes.length) {
            throw new IOException("Could not completely read file " + file.getName());
        }

        // Close the input stream and return bytes
        is.close();
        return bytes;
    }
}